Clostridial collagenase aggravates the systemic inflammatory response in rats with partial-thickness burns

Clostridial collagenase A (CCA) has been shown effective in degrading collagen in eschar tissue and promoting healing in partial-thickness burns. As there are also reports of fever, leukocytosis, increased C-reactive protein (CRP) levels and septic complications during treatment with CCA, we aimed to determine in rats whether CCA aggravates the systemic inflammatory response.

Rats with partial-thickness burns were randomly divided into groups with either no dressing (ND), povidone-iodine dressing (PID) or CCA dressing (CCAD). Body weights and temperatures, blood leukocyte counts, and serum levels of CRP, interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha), were measured at 0, 3, and 24h and days 3 and 7 from burn. Wounds were cultured on days 1, 3 and 7 and burn depth was evaluated on day 1.

Body weights for all groups were significantly lower after burn, with highest loss (25.5%) in the CCAD group. At 3h a significant drop in rectal temperature was noted in all groups. The CCAD group had higher rectal temperature levels than the PID group on days 3 and 7 (p<0.05). Changes in serum levels of CRP, IL-1 beta, IL-6 and TNF-alpha were not significant in the ND and PID groups; the CCAD group showed a significant rise in serum levels of CRP on day 1, of IL-6 on day 3 and of TNF-alpha on day 7. Wound infection was more common in CCAD group and increased on days 3 and 7, but this was insignificant.

CCA aggravated the systemic inflammatory response in rats with partial-thickness burns, which is accompanied by a higher risk of infection.